He said: “These canisters are used domestically more in the summer by campers and those using barbecues.

“We would urge those using them to follow the procedures carefully and dispose of used canisters at recycling centres.”

The inquest heard how watch manager David Robinson was among two fire crews who responded to four calls from neighbours, including one saying that 'a house had blown up' and was on fire.

Officer Robinson said Mr Chadwick approached him when he arrived at the scene on September 8 last year.

He said: “He had no clothes on the top half of his body, his hair was singed and there were burns to both his arms.

“I think he was in shock but was talking relatively coherently. He said ’it was supposed to be empty’ and ‘there wasn’t supposed to be anything in it’.”

While Mr Chadwick was being treated, firefighters tackled the blaze, which had broken out in several places on the ground floor and yard at around 7.40pm.

A second, smaller explosion occurred because a gas meter had been damaged in an outhouse, leading to a small leak of domestic gas.

Mr Chadwick was initially taken to Royal Blackburn Hospital before being transferred to a specialist burns unit at Wakefield.

He died on September 18 from respiratory distress syndrome, a lung infection caused by reaction to traumatic injuries such as burns.

A detailed fire investigation report was outlined to the inquest by incident intelligence officer Steve Green.

He said a metal Calorgas container was found in the back yard with the valve opened by about three turns.

He said: “Butane gas would have been released. This type of gas is twice as heavy as air and acts very much like water, staying close to the ground and finding any available space.

“It wouldn’t have taken a lot of gas to spread quickly through the house.

“The canister itself did not explode, it was the released gas.

“For it to ignite it would have needed to be in concentrations of between two and 10 per cent and would need to come into contact with a naked flame, in this case the gas fire in the lounge.

“There will have been a sudden flash explosion which swept through the house and yard.”

Officer Green said it was likely that Mr Chadwick was in the back yard at the time of the explosion.

The inquest heard that the gas cylinder was likely to have been in the back yard area for several years previously, pre-dating Mr Chadwick moving into the property.

Recording a verdict of accidental death, East Lancashire coroner Richard Taylor said there was no explanation as to why the valve on the gas container had been opened and there was no evidence to suggest he wished to harm himself.

Yesterday a neighbour, who did not wish to be named, said he heard a 'massive bang' that evening.

“It was like a car backfiring but three or four times louder,” he said.

“I looked out onto the street and the neighbours out. The fire engines were there within a couple of minutes. I saw Jeffrey on the street, he was shirtless and being attended to.